Red eye, the result of the light from the flash reflecting off the back of the retina, is not a phenomenon that is new to digital photography. It most commonly occurs when using a camera with a pop-up flash directly over the lens. While it is always best if it can be avoided there are ways to reduce its appearance when it occurs. 

The tools we need for this job are in the Develop module. Select your photos and press D to jump on over. There are 2 techniques I’d like to show you. One only works on human eyes, but the other can be used for both humans and pets.

Reducing Red Eye

Read Correcting Red Eye over at peachpit.com.